1. Field of the Invention
The present invention relates generally to microdevices and more particularly to individual multisurfaced microdevice systems that are independently operable for small-scale applications and that are intercommunicatively assembleable to form microdevice system arrays for large scale applications.
2. Background Art
Current sensing and control systems tend to be complex and expensive. Typical systems include mechanical or laser gyros integrated with sensitive accelerometers and timing subsystems on circuit cards with many microprocessors and signal processing circuitry. Although some key components, particularly accelerometers, have been miniaturized in solid state microelectromechanical system (MEMS) devices, there does not exist a universal, complete and versatile sensing, actuating and controlling “system-on-a-chip” in a very small, low-power package that effectively lends itself to a plethora of diverse applications.
Furthermore, although solid-state microprocessors, sensors, microelectromechanical systems and energy transmitters, for example, light-emitting diodes (LED's), have undergone revolutionary development for three decades, almost all these diverse devices are fabricated on nearly flat, two-dimensional substrates. A large majority of such devices are fabricated on crystalline silicon wafers having a thickness of approximately 2 millimeters. It is unusual for such devices to have surface feature relief exceeding approximately 100 microns in depth or height.
Large investments have been made in existing microcircuit production facilities. Large-scale production is done by expensive robotic machines in highly automated clean-room environments. Typically, some hundred different operations must be performed on each semiconductor wafer surface; and the wafers must be precisely indexed and transported between some twenty machines. An improvement in this system can be realized by fabricating microdevices on both surfaces of wafers; and a need for such an improvement exists, especially given the rapidly expanding demand for more versatile and highly integrated microdevices. A major retooling of existing production lines, however, would be expensive and time consuming.
To facilitate such an improvement without major retooling, two primary fabrication concerns must be addressed: precision-made microdevices already fabricated on one surface of a wafer must not be damaged during the process of fabricating microdevices on its opposite surface, and the disposition and registration of the microdevices on opposing surfaces must be precise.
The present invention addresses such problems. It also provides technology that facilitates, by using techniques such as convergent assembly and biomimetics, the manufacture of extendable arrays of many identical elements finding application in, for example, sensing, optics, guidance, stabilization, motility and robotics that function together for large-scale applications. The performance of the new technology equals or exceeds that of previous ad hoc subsystems while also providing reductions in size, energy consumption, cost and complexity of application-oriented systems. Moreover, much of the present invention can be fabricated using present technology, thus further reducing cost and fabrication time.